Modeling of Two-Phase Flow in Oil Wells Using a Simplified Two-Fluid Model

Abstract

In this work, with the idea of finding a simplified, numerically stable, one-dimensional, time-dependent two-fluid mathematical model whose predictions are in agreement with oil wells data, a study of the accumulative terms effect on the numerical stability and predictions of a general two-fluid model, was carried out. The fluids considered in oil wells were water, oil, and gas. The liquid phase in the model is formed by water and oil with pseudoproperties. The model is able to predict pressure, volume fraction, velocity, and temperature for both phases. The numerical solution of the model, which consists of mass, momentum, and energy conservation equations, is based on the finite difference technique in the implicit scheme. The thermodynamic and transport properties of the fluids are estimated by black-oil PVT correlations. It was observed that, a numerically stable model, with acceptable predictions has to take into account the accumulative terms for the liquid volume fraction, gas velocity, and liquid temperature. Numerical results are in agreement with field data and theoretical results reported in literature.